[Peter Finke]

You must think like this: The aquarium water is always worse than the flowing blackwater of the wet rainforest. The best conditions for our Paros would be slowly streaming fresh waters. But in the normal tank this is not possible. The more often you change water and the more you change big quantities the better. But normal aquarists are lazy. They change every four days or every week a certain part of the old water. The more you combat your laziness and change more often more water the better.
Fortunately, most of our Paros are able to stand the medium standard changing conditions, but that does not mean this to be good; it’s more or less acceptable only. The problem is that of a structure quite different from nature: the aquarium. Water change is an imperfect means to imitate the constant flow of best waters without germs. The more you fight your laziness and change more frequent and bigger quantities, the better. If you succeed staying lazy and change little, you can be lucky with certain species, but you will probably not with other. At any rate you play with the adaptability of organisms that are far less adaptable than most of other aquarium inhabitants.